A series of studies is being conducted to determine the following: 1. The relationships between auditory processing deficits, speech perception skills, attention disorders, and speech and language development in hyperactive boys with and without learning disorders; 2. The effects of stimulants on the speech, language and communicative skills of language-disordered hyperactive boys; 3. Whether auditory processing disorders in hyperactive boys with and without disorders in speech, language and reading respond similarly to the administration of dextroamphetamine; and 4. Whether the effects of stimulant drugs on auditory processing disorders in language-impaired children are related to the effects of stimulants on language processing and speech fluency. 5. The training effects of task repetition in auditory processing skills in four distinct groups of learning impaired children while not receiving drugs. 6. The effects of different neuropharmacologic agents on auditory processing and language skills in hyperactive subjects.